All things related to multicast

[Chris Rapier <>]

Recently I was forwarded a request about an MSDP dumping tool. I believe
they were looking for something that would sit on (actually jump on and
off) a port and request SA_TLV packets. 

So I wrote one as an exercise. Its a pretty basic perl program but it
seems to do  what was requested with some level of ability. I'm aware
that this might not be the most efficient tool and it, in fact, might
have some significant problems. I want to actively encourage your
critiques, comments, and suggestions. As I'm not on this list yet be
sure to CC me in any replies.

You can find the tool at:

http://www.ncne.nlanr.net/tools/multicast.html
Its near the bottom of the page. 
I've been calling it msdpdump.
The code itself contains most of the documentation and I hope the
comments will explain some of the choices I made during the writing of
this.

I also created an online version that I should have on the production
web server inside of 10 minutes. You'll be able to access that at
http://www.ncne.nlanr.net/cgi-bin/webmsdpdump 

If you try out the online version please be aware that it only peers
with two router (namely ours) and the routine to back off from a busy
port and then continue is somewhat unproven (but getting more practice
as time goes on). We're also seeing a problem that might be caused by
the peer going through a firewall. Hopefully we'll resolve that soon but
for now it just slows down tool a little bit (1 second wait time between
connection attempts after a failure).

However, what you can do with the online version is compare a router
that peers only with the vBNS (beast.psc.net) and a router that only
peers with Abilene(killifish.psc.net). That might prove interesting to
some.

Again, please send me any comments or suggestions. I'm looking for your
input to improve the utility of this tool.

Chris Rapier
Network Programmer Flunky Type
NCNE NLANR ES